1. Field of the Invention
The present disclosure relates to image processing apparatuses, image forming systems, image forming methods and programs.
2. Description of the Related Art
Conventionally, an image reading apparatus such as a scanner for reading an image formed on a document such as a paper is known. Also, a method is known, in which so called skew correction for correcting an inclination is performed when the document is read by the reading apparatus being inclined with respect to a main scanning direction or a sub-scanning direction.
Among methods for correcting the inclination of the document, a method is known, in which distal end edge data is searched through an edge extraction process to correct the inclination of the document based on the searched distal end edge data (for example, Patent Document 1).
Also, a method is known, in which dusts and dirt on a reading surface of the document is detected to distinguish a vertical line in the document from vertical lines caused by the dusts and dirt, thereby correcting the inclination of the document (for example, see Patent Document 2).
However, in a case where a recording medium such as a paper is folded by a user, etc., an edge portion of the recording medium may be chipped. When the edge portion of the recording medium is chipped as described above, coordinates of the edge portion of the recording medium may be calculated, in the inclination correction of the recording medium, based on an edge portion caused by the fold.